1 files changed, 313 insertions, 300 deletions

diff --git a/net/sunrpc/svc_xprt.c b/net/sunrpc/svc_xprt.c
index 62c7919ea610..6973184ff667 100644
--- a/net/sunrpc/svc_xprt.c
+++ b/net/sunrpc/svc_xprt.c
@@ -9,7 +9,6 @@
 #include <linux/sched/mm.h>
 #include <linux/errno.h>
 #include <linux/freezer.h>
-#include <linux/kthread.h>
 #include <linux/slab.h>
 #include <net/sock.h>
 #include <linux/sunrpc/addr.h>
@@ -17,6 +16,7 @@
 #include <linux/sunrpc/svc_xprt.h>
 #include <linux/sunrpc/svcsock.h>
 #include <linux/sunrpc/xprt.h>
+#include <linux/sunrpc/bc_xprt.h>
 #include <linux/module.h>
 #include <linux/netdevice.h>
 #include <trace/events/sunrpc.h>
@@ -46,7 +46,6 @@ static LIST_HEAD(svc_xprt_class_list);
 
 /* SMP locking strategy:
  *
- *	svc_pool->sp_lock protects most of the fields of that pool.
  *	svc_serv->sv_lock protects sv_tempsocks, sv_permsocks, sv_tmpcnt.
  *	when both need to be taken (rare), svc_serv->sv_lock is first.
  *	The "service mutex" protects svc_serv->sv_nrthread.
@@ -158,6 +157,7 @@ int svc_print_xprts(char *buf, int maxlen)
  */
 void svc_xprt_deferred_close(struct svc_xprt *xprt)
 {
+	trace_svc_xprt_close(xprt);
 	if (!test_and_set_bit(XPT_CLOSE, &xprt->xpt_flags))
 		svc_xprt_enqueue(xprt);
 }
@@ -201,7 +201,6 @@ void svc_xprt_init(struct net *net, struct svc_xprt_class *xcl,
 	kref_init(&xprt->xpt_ref);
 	xprt->xpt_server = serv;
 	INIT_LIST_HEAD(&xprt->xpt_list);
-	INIT_LIST_HEAD(&xprt->xpt_ready);
 	INIT_LIST_HEAD(&xprt->xpt_deferred);
 	INIT_LIST_HEAD(&xprt->xpt_users);
 	mutex_init(&xprt->xpt_mutex);
@@ -212,51 +211,6 @@ void svc_xprt_init(struct net *net, struct svc_xprt_class *xcl,
 }
 EXPORT_SYMBOL_GPL(svc_xprt_init);
 
-static struct svc_xprt *__svc_xpo_create(struct svc_xprt_class *xcl,
-					 struct svc_serv *serv,
-					 struct net *net,
-					 const int family,
-					 const unsigned short port,
-					 int flags)
-{
-	struct sockaddr_in sin = {
-		.sin_family		= AF_INET,
-		.sin_addr.s_addr	= htonl(INADDR_ANY),
-		.sin_port		= htons(port),
-	};
-#if IS_ENABLED(CONFIG_IPV6)
-	struct sockaddr_in6 sin6 = {
-		.sin6_family		= AF_INET6,
-		.sin6_addr		= IN6ADDR_ANY_INIT,
-		.sin6_port		= htons(port),
-	};
-#endif
-	struct svc_xprt *xprt;
-	struct sockaddr *sap;
-	size_t len;
-
-	switch (family) {
-	case PF_INET:
-		sap = (struct sockaddr *)&sin;
-		len = sizeof(sin);
-		break;
-#if IS_ENABLED(CONFIG_IPV6)
-	case PF_INET6:
-		sap = (struct sockaddr *)&sin6;
-		len = sizeof(sin6);
-		break;
-#endif
-	default:
-		return ERR_PTR(-EAFNOSUPPORT);
-	}
-
-	xprt = xcl->xcl_ops->xpo_create(serv, net, sap, len, flags);
-	if (IS_ERR(xprt))
-		trace_svc_xprt_create_err(serv->sv_program->pg_name,
-					  xcl->xcl_name, sap, len, xprt);
-	return xprt;
-}
-
 /**
  * svc_xprt_received - start next receiver thread
  * @xprt: controlling transport
@@ -295,9 +249,8 @@ void svc_add_new_perm_xprt(struct svc_serv *serv, struct svc_xprt *new)
 }
 
 static int _svc_xprt_create(struct svc_serv *serv, const char *xprt_name,
-			    struct net *net, const int family,
-			    const unsigned short port, int flags,
-			    const struct cred *cred)
+			    struct net *net, struct sockaddr *sap,
+			    size_t len, int flags, const struct cred *cred)
 {
 	struct svc_xprt_class *xcl;
 
@@ -313,8 +266,11 @@ static int _svc_xprt_create(struct svc_serv *serv, const char *xprt_name,
 			goto err;
 
 		spin_unlock(&svc_xprt_class_lock);
-		newxprt = __svc_xpo_create(xcl, serv, net, family, port, flags);
+		newxprt = xcl->xcl_ops->xpo_create(serv, net, sap, len, flags);
 		if (IS_ERR(newxprt)) {
+			trace_svc_xprt_create_err(serv->sv_programs->pg_name,
+						  xcl->xcl_name, sap, len,
+						  newxprt);
 			module_put(xcl->xcl_owner);
 			return PTR_ERR(newxprt);
 		}
@@ -331,6 +287,48 @@ static int _svc_xprt_create(struct svc_serv *serv, const char *xprt_name,
 }
 
 /**
+ * svc_xprt_create_from_sa - Add a new listener to @serv from socket address
+ * @serv: target RPC service
+ * @xprt_name: transport class name
+ * @net: network namespace
+ * @sap: socket address pointer
+ * @flags: SVC_SOCK flags
+ * @cred: credential to bind to this transport
+ *
+ * Return local xprt port on success or %-EPROTONOSUPPORT on failure
+ */
+int svc_xprt_create_from_sa(struct svc_serv *serv, const char *xprt_name,
+			    struct net *net, struct sockaddr *sap,
+			    int flags, const struct cred *cred)
+{
+	size_t len;
+	int err;
+
+	switch (sap->sa_family) {
+	case AF_INET:
+		len = sizeof(struct sockaddr_in);
+		break;
+#if IS_ENABLED(CONFIG_IPV6)
+	case AF_INET6:
+		len = sizeof(struct sockaddr_in6);
+		break;
+#endif
+	default:
+		return -EAFNOSUPPORT;
+	}
+
+	err = _svc_xprt_create(serv, xprt_name, net, sap, len, flags, cred);
+	if (err == -EPROTONOSUPPORT) {
+		request_module("svc%s", xprt_name);
+		err = _svc_xprt_create(serv, xprt_name, net, sap, len, flags,
+				       cred);
+	}
+
+	return err;
+}
+EXPORT_SYMBOL_GPL(svc_xprt_create_from_sa);
+
+/**
  * svc_xprt_create - Add a new listener to @serv
  * @serv: target RPC service
  * @xprt_name: transport class name
@@ -340,23 +338,41 @@ static int _svc_xprt_create(struct svc_serv *serv, const char *xprt_name,
  * @flags: SVC_SOCK flags
  * @cred: credential to bind to this transport
  *
- * Return values:
- *   %0: New listener added successfully
- *   %-EPROTONOSUPPORT: Requested transport type not supported
+ * Return local xprt port on success or %-EPROTONOSUPPORT on failure
  */
 int svc_xprt_create(struct svc_serv *serv, const char *xprt_name,
 		    struct net *net, const int family,
 		    const unsigned short port, int flags,
 		    const struct cred *cred)
 {
-	int err;
+	struct sockaddr_in sin = {
+		.sin_family		= AF_INET,
+		.sin_addr.s_addr	= htonl(INADDR_ANY),
+		.sin_port		= htons(port),
+	};
+#if IS_ENABLED(CONFIG_IPV6)
+	struct sockaddr_in6 sin6 = {
+		.sin6_family		= AF_INET6,
+		.sin6_addr		= IN6ADDR_ANY_INIT,
+		.sin6_port		= htons(port),
+	};
+#endif
+	struct sockaddr *sap;
 
-	err = _svc_xprt_create(serv, xprt_name, net, family, port, flags, cred);
-	if (err == -EPROTONOSUPPORT) {
-		request_module("svc%s", xprt_name);
-		err = _svc_xprt_create(serv, xprt_name, net, family, port, flags, cred);
+	switch (family) {
+	case PF_INET:
+		sap = (struct sockaddr *)&sin;
+		break;
+#if IS_ENABLED(CONFIG_IPV6)
+	case PF_INET6:
+		sap = (struct sockaddr *)&sin6;
+		break;
+#endif
+	default:
+		return -EAFNOSUPPORT;
 	}
-	return err;
+
+	return svc_xprt_create_from_sa(serv, xprt_name, net, sap, flags, cred);
 }
 EXPORT_SYMBOL_GPL(svc_xprt_create);
 
@@ -434,6 +450,7 @@ static bool svc_xprt_ready(struct svc_xprt *xprt)
 	smp_rmb();
 	xpt_flags = READ_ONCE(xprt->xpt_flags);
 
+	trace_svc_xprt_enqueue(xprt, xpt_flags);
 	if (xpt_flags & BIT(XPT_BUSY))
 		return false;
 	if (xpt_flags & (BIT(XPT_CONN) | BIT(XPT_CLOSE) | BIT(XPT_HANDSHAKE)))
@@ -456,7 +473,6 @@ static bool svc_xprt_ready(struct svc_xprt *xprt)
 void svc_xprt_enqueue(struct svc_xprt *xprt)
 {
 	struct svc_pool *pool;
-	struct svc_rqst	*rqstp = NULL;
 
 	if (!svc_xprt_ready(xprt))
 		return;
@@ -472,25 +488,10 @@ void svc_xprt_enqueue(struct svc_xprt *xprt)
 	pool = svc_pool_for_cpu(xprt->xpt_server);
 
 	percpu_counter_inc(&pool->sp_sockets_queued);
-	spin_lock_bh(&pool->sp_lock);
-	list_add_tail(&xprt->xpt_ready, &pool->sp_sockets);
-	spin_unlock_bh(&pool->sp_lock);
-
-	/* find a thread for this xprt */
-	rcu_read_lock();
-	list_for_each_entry_rcu(rqstp, &pool->sp_all_threads, rq_all) {
-		if (test_and_set_bit(RQ_BUSY, &rqstp->rq_flags))
-			continue;
-		percpu_counter_inc(&pool->sp_threads_woken);
-		rqstp->rq_qtime = ktime_get();
-		wake_up_process(rqstp->rq_task);
-		goto out_unlock;
-	}
-	set_bit(SP_CONGESTED, &pool->sp_flags);
-	rqstp = NULL;
-out_unlock:
-	rcu_read_unlock();
-	trace_svc_xprt_enqueue(xprt, rqstp);
+	xprt->xpt_qtime = ktime_get();
+	lwq_enqueue(&xprt->xpt_ready, &pool->sp_xprts);
+
+	svc_pool_wake_idle_thread(pool);
 }
 EXPORT_SYMBOL_GPL(svc_xprt_enqueue);
 
@@ -501,18 +502,9 @@ static struct svc_xprt *svc_xprt_dequeue(struct svc_pool *pool)
 {
 	struct svc_xprt	*xprt = NULL;
 
-	if (list_empty(&pool->sp_sockets))
-		goto out;
-
-	spin_lock_bh(&pool->sp_lock);
-	if (likely(!list_empty(&pool->sp_sockets))) {
-		xprt = list_first_entry(&pool->sp_sockets,
-					struct svc_xprt, xpt_ready);
-		list_del_init(&xprt->xpt_ready);
+	xprt = lwq_dequeue(&pool->sp_xprts, struct svc_xprt, xpt_ready);
+	if (xprt)
 		svc_xprt_get(xprt);
-	}
-	spin_unlock_bh(&pool->sp_lock);
-out:
 	return xprt;
 }
 
@@ -581,7 +573,10 @@ static void svc_xprt_release(struct svc_rqst *rqstp)
 	svc_xprt_put(xprt);
 }
 
-/*
+/**
+ * svc_wake_up - Wake up a service thread for non-transport work
+ * @serv: RPC service
+ *
  * Some svc_serv's will have occasional work to do, even when a xprt is not
  * waiting to be serviced. This function is there to "kick" a task in one of
  * those services so that it can wake up and do that work. Note that we only
@@ -590,27 +585,10 @@ static void svc_xprt_release(struct svc_rqst *rqstp)
  */
 void svc_wake_up(struct svc_serv *serv)
 {
-	struct svc_rqst	*rqstp;
-	struct svc_pool *pool;
-
-	pool = &serv->sv_pools[0];
+	struct svc_pool *pool = &serv->sv_pools[0];
 
-	rcu_read_lock();
-	list_for_each_entry_rcu(rqstp, &pool->sp_all_threads, rq_all) {
-		/* skip any that aren't queued */
-		if (test_bit(RQ_BUSY, &rqstp->rq_flags))
-			continue;
-		rcu_read_unlock();
-		wake_up_process(rqstp->rq_task);
-		trace_svc_wake_up(rqstp->rq_task->pid);
-		return;
-	}
-	rcu_read_unlock();
-
-	/* No free entries available */
 	set_bit(SP_TASK_PENDING, &pool->sp_flags);
-	smp_wmb();
-	trace_svc_wake_up(0);
+	svc_pool_wake_idle_thread(pool);
 }
 EXPORT_SYMBOL_GPL(svc_wake_up);
 
@@ -629,7 +607,8 @@ int svc_port_is_privileged(struct sockaddr *sin)
 }
 
 /*
- * Make sure that we don't have too many active connections. If we have,
+ * Make sure that we don't have too many connections that have not yet
+ * demonstrated that they have access to the NFS server. If we have,
  * something must be dropped. It's not clear what will happen if we allow
  * "too many" connections, but when dealing with network-facing software,
  * we have to code defensively. Here we do that by imposing hard limits.
@@ -641,34 +620,26 @@ int svc_port_is_privileged(struct sockaddr *sin)
  * The only somewhat efficient mechanism would be if drop old
  * connections from the same IP first. But right now we don't even
  * record the client IP in svc_sock.
- *
- * single-threaded services that expect a lot of clients will probably
- * need to set sv_maxconn to override the default value which is based
- * on the number of threads
  */
 static void svc_check_conn_limits(struct svc_serv *serv)
 {
-	unsigned int limit = serv->sv_maxconn ? serv->sv_maxconn :
-				(serv->sv_nrthreads+3) * 20;
-
-	if (serv->sv_tmpcnt > limit) {
-		struct svc_xprt *xprt = NULL;
+	if (serv->sv_tmpcnt > XPT_MAX_TMP_CONN) {
+		struct svc_xprt *xprt = NULL, *xprti;
 		spin_lock_bh(&serv->sv_lock);
 		if (!list_empty(&serv->sv_tempsocks)) {
-			/* Try to help the admin */
-			net_notice_ratelimited("%s: too many open connections, consider increasing the %s\n",
-					       serv->sv_name, serv->sv_maxconn ?
-					       "max number of connections" :
-					       "number of threads");
 			/*
 			 * Always select the oldest connection. It's not fair,
-			 * but so is life
+			 * but nor is life.
 			 */
-			xprt = list_entry(serv->sv_tempsocks.prev,
-					  struct svc_xprt,
-					  xpt_list);
-			set_bit(XPT_CLOSE, &xprt->xpt_flags);
-			svc_xprt_get(xprt);
+			list_for_each_entry_reverse(xprti, &serv->sv_tempsocks,
+						    xpt_list) {
+				if (!test_bit(XPT_PEER_VALID, &xprti->xpt_flags)) {
+					xprt = xprti;
+					set_bit(XPT_CLOSE, &xprt->xpt_flags);
+					svc_xprt_get(xprt);
+					break;
+				}
+			}
 		}
 		spin_unlock_bh(&serv->sv_lock);
 
@@ -679,32 +650,22 @@ static void svc_check_conn_limits(struct svc_serv *serv)
 	}
 }
 
-static int svc_alloc_arg(struct svc_rqst *rqstp)
+static bool svc_alloc_arg(struct svc_rqst *rqstp)
 {
-	struct svc_serv *serv = rqstp->rq_server;
 	struct xdr_buf *arg = &rqstp->rq_arg;
 	unsigned long pages, filled, ret;
 
-	pages = (serv->sv_max_mesg + 2 * PAGE_SIZE) >> PAGE_SHIFT;
-	if (pages > RPCSVC_MAXPAGES) {
-		pr_warn_once("svc: warning: pages=%lu > RPCSVC_MAXPAGES=%lu\n",
-			     pages, RPCSVC_MAXPAGES);
-		/* use as many pages as possible */
-		pages = RPCSVC_MAXPAGES;
-	}
-
+	pages = rqstp->rq_maxpages;
 	for (filled = 0; filled < pages; filled = ret) {
-		ret = alloc_pages_bulk_array_node(GFP_KERNEL,
-						  rqstp->rq_pool->sp_id,
-						  pages, rqstp->rq_pages);
+		ret = alloc_pages_bulk(GFP_KERNEL, pages, rqstp->rq_pages);
 		if (ret > filled)
 			/* Made progress, don't sleep yet */
 			continue;
 
-		set_current_state(TASK_INTERRUPTIBLE);
-		if (signalled() || kthread_should_stop()) {
+		set_current_state(TASK_IDLE);
+		if (svc_thread_should_stop(rqstp)) {
 			set_current_state(TASK_RUNNING);
-			return -EINTR;
+			return false;
 		}
 		trace_svc_alloc_arg_err(pages, ret);
 		memalloc_retry_wait(GFP_KERNEL);
@@ -723,84 +684,64 @@ static int svc_alloc_arg(struct svc_rqst *rqstp)
 	arg->tail[0].iov_len = 0;
 
 	rqstp->rq_xid = xdr_zero;
-	return 0;
+	return true;
 }
 
 static bool
-rqst_should_sleep(struct svc_rqst *rqstp)
+svc_thread_should_sleep(struct svc_rqst *rqstp)
 {
 	struct svc_pool		*pool = rqstp->rq_pool;
 
 	/* did someone call svc_wake_up? */
-	if (test_and_clear_bit(SP_TASK_PENDING, &pool->sp_flags))
+	if (test_bit(SP_TASK_PENDING, &pool->sp_flags))
 		return false;
 
 	/* was a socket queued? */
-	if (!list_empty(&pool->sp_sockets))
+	if (!lwq_empty(&pool->sp_xprts))
 		return false;
 
 	/* are we shutting down? */
-	if (signalled() || kthread_should_stop())
+	if (svc_thread_should_stop(rqstp))
 		return false;
 
-	/* are we freezing? */
-	if (freezing(current))
-		return false;
+#if defined(CONFIG_SUNRPC_BACKCHANNEL)
+	if (svc_is_backchannel(rqstp)) {
+		if (!lwq_empty(&rqstp->rq_server->sv_cb_list))
+			return false;
+	}
+#endif
 
 	return true;
 }
 
-static struct svc_xprt *svc_get_next_xprt(struct svc_rqst *rqstp, long timeout)
+static void svc_thread_wait_for_work(struct svc_rqst *rqstp)
 {
-	struct svc_pool		*pool = rqstp->rq_pool;
-	long			time_left = 0;
-
-	/* rq_xprt should be clear on entry */
-	WARN_ON_ONCE(rqstp->rq_xprt);
-
-	rqstp->rq_xprt = svc_xprt_dequeue(pool);
-	if (rqstp->rq_xprt)
-		goto out_found;
-
-	/*
-	 * We have to be able to interrupt this wait
-	 * to bring down the daemons ...
-	 */
-	set_current_state(TASK_INTERRUPTIBLE);
-	smp_mb__before_atomic();
-	clear_bit(SP_CONGESTED, &pool->sp_flags);
-	clear_bit(RQ_BUSY, &rqstp->rq_flags);
-	smp_mb__after_atomic();
-
-	if (likely(rqst_should_sleep(rqstp)))
-		time_left = schedule_timeout(timeout);
-	else
+	struct svc_pool *pool = rqstp->rq_pool;
+
+	if (svc_thread_should_sleep(rqstp)) {
+		set_current_state(TASK_IDLE | TASK_FREEZABLE);
+		llist_add(&rqstp->rq_idle, &pool->sp_idle_threads);
+		if (likely(svc_thread_should_sleep(rqstp)))
+			schedule();
+
+		while (!llist_del_first_this(&pool->sp_idle_threads,
+					     &rqstp->rq_idle)) {
+			/* Work just became available.  This thread can only
+			 * handle it after removing rqstp from the idle
+			 * list. If that attempt failed, some other thread
+			 * must have queued itself after finding no
+			 * work to do, so that thread has taken responsibly
+			 * for this new work.  This thread can safely sleep
+			 * until woken again.
+			 */
+			schedule();
+			set_current_state(TASK_IDLE | TASK_FREEZABLE);
+		}
 		__set_current_state(TASK_RUNNING);
-
+	} else {
+		cond_resched();
+	}
 	try_to_freeze();
-
-	set_bit(RQ_BUSY, &rqstp->rq_flags);
-	smp_mb__after_atomic();
-	rqstp->rq_xprt = svc_xprt_dequeue(pool);
-	if (rqstp->rq_xprt)
-		goto out_found;
-
-	if (!time_left)
-		percpu_counter_inc(&pool->sp_threads_timedout);
-
-	if (signalled() || kthread_should_stop())
-		return ERR_PTR(-EINTR);
-	return ERR_PTR(-EAGAIN);
-out_found:
-	/* Normally we will wait up to 5 seconds for any required
-	 * cache information to be provided.
-	 */
-	if (!test_bit(SP_CONGESTED, &pool->sp_flags))
-		rqstp->rq_chandle.thread_wait = 5*HZ;
-	else
-		rqstp->rq_chandle.thread_wait = 1*HZ;
-	trace_svc_xprt_dequeue(rqstp);
-	return rqstp->rq_xprt;
 }
 
 static void svc_add_new_temp_xprt(struct svc_serv *serv, struct svc_xprt *newxpt)
@@ -819,7 +760,7 @@ static void svc_add_new_temp_xprt(struct svc_serv *serv, struct svc_xprt *newxpt
 	svc_xprt_received(newxpt);
 }
 
-static int svc_handle_xprt(struct svc_rqst *rqstp, struct svc_xprt *xprt)
+static void svc_handle_xprt(struct svc_rqst *rqstp, struct svc_xprt *xprt)
 {
 	struct svc_serv *serv = rqstp->rq_server;
 	int len = 0;
@@ -860,75 +801,95 @@ static int svc_handle_xprt(struct svc_rqst *rqstp, struct svc_xprt *xprt)
 			len = xprt->xpt_ops->xpo_recvfrom(rqstp);
 		rqstp->rq_reserved = serv->sv_max_mesg;
 		atomic_add(rqstp->rq_reserved, &xprt->xpt_reserved);
+		if (len <= 0)
+			goto out;
+
+		trace_svc_xdr_recvfrom(&rqstp->rq_arg);
+
+		clear_bit(XPT_OLD, &xprt->xpt_flags);
+
+		rqstp->rq_chandle.defer = svc_defer;
+
+		if (serv->sv_stats)
+			serv->sv_stats->netcnt++;
+		percpu_counter_inc(&rqstp->rq_pool->sp_messages_arrived);
+		rqstp->rq_stime = ktime_get();
+		svc_process(rqstp);
 	} else
 		svc_xprt_received(xprt);
 
 out:
-	return len;
+	rqstp->rq_res.len = 0;
+	svc_xprt_release(rqstp);
 }
 
-/*
- * Receive the next request on any transport.  This code is carefully
- * organised not to touch any cachelines in the shared svc_serv
- * structure, only cachelines in the local svc_pool.
+static void svc_thread_wake_next(struct svc_rqst *rqstp)
+{
+	if (!svc_thread_should_sleep(rqstp))
+		/* More work pending after I dequeued some,
+		 * wake another worker
+		 */
+		svc_pool_wake_idle_thread(rqstp->rq_pool);
+}
+
+/**
+ * svc_recv - Receive and process the next request on any transport
+ * @rqstp: an idle RPC service thread
+ *
+ * This code is carefully organised not to touch any cachelines in
+ * the shared svc_serv structure, only cachelines in the local
+ * svc_pool.
  */
-int svc_recv(struct svc_rqst *rqstp, long timeout)
+void svc_recv(struct svc_rqst *rqstp)
 {
-	struct svc_xprt		*xprt = NULL;
-	struct svc_serv		*serv = rqstp->rq_server;
-	int			len, err;
+	struct svc_pool *pool = rqstp->rq_pool;
 
-	err = svc_alloc_arg(rqstp);
-	if (err)
-		goto out;
+	if (!svc_alloc_arg(rqstp))
+		return;
 
-	try_to_freeze();
-	cond_resched();
-	err = -EINTR;
-	if (signalled() || kthread_should_stop())
-		goto out;
+	svc_thread_wait_for_work(rqstp);
 
-	xprt = svc_get_next_xprt(rqstp, timeout);
-	if (IS_ERR(xprt)) {
-		err = PTR_ERR(xprt);
-		goto out;
-	}
+	clear_bit(SP_TASK_PENDING, &pool->sp_flags);
 
-	len = svc_handle_xprt(rqstp, xprt);
+	if (svc_thread_should_stop(rqstp)) {
+		svc_thread_wake_next(rqstp);
+		return;
+	}
 
-	/* No data, incomplete (TCP) read, or accept() */
-	err = -EAGAIN;
-	if (len <= 0)
-		goto out_release;
+	rqstp->rq_xprt = svc_xprt_dequeue(pool);
+	if (rqstp->rq_xprt) {
+		struct svc_xprt *xprt = rqstp->rq_xprt;
 
-	trace_svc_xdr_recvfrom(&rqstp->rq_arg);
+		svc_thread_wake_next(rqstp);
+		/* Normally we will wait up to 5 seconds for any required
+		 * cache information to be provided.  When there are no
+		 * idle threads, we reduce the wait time.
+		 */
+		if (pool->sp_idle_threads.first)
+			rqstp->rq_chandle.thread_wait = 5 * HZ;
+		else
+			rqstp->rq_chandle.thread_wait = 1 * HZ;
 
-	clear_bit(XPT_OLD, &xprt->xpt_flags);
+		trace_svc_xprt_dequeue(rqstp);
+		svc_handle_xprt(rqstp, xprt);
+	}
 
-	rqstp->rq_chandle.defer = svc_defer;
+#if defined(CONFIG_SUNRPC_BACKCHANNEL)
+	if (svc_is_backchannel(rqstp)) {
+		struct svc_serv *serv = rqstp->rq_server;
+		struct rpc_rqst *req;
 
-	if (serv->sv_stats)
-		serv->sv_stats->netcnt++;
-	rqstp->rq_stime = ktime_get();
-	return len;
-out_release:
-	rqstp->rq_res.len = 0;
-	svc_xprt_release(rqstp);
-out:
-	return err;
+		req = lwq_dequeue(&serv->sv_cb_list,
+				  struct rpc_rqst, rq_bc_list);
+		if (req) {
+			svc_thread_wake_next(rqstp);
+			svc_process_bc(req, rqstp);
+		}
+	}
+#endif
 }
 EXPORT_SYMBOL_GPL(svc_recv);
 
-/*
- * Drop request
- */
-void svc_drop(struct svc_rqst *rqstp)
-{
-	trace_svc_drop(rqstp);
-	svc_xprt_release(rqstp);
-}
-EXPORT_SYMBOL_GPL(svc_drop);
-
 /**
  * svc_send - Return reply to client
  * @rqstp: RPC transaction context
@@ -941,8 +902,6 @@ void svc_send(struct svc_rqst *rqstp)
 	int status;
 
 	xprt = rqstp->rq_xprt;
-	if (!xprt)
-		return;
 
 	/* calculate over-all length */
 	xb = &rqstp->rq_res;
@@ -955,7 +914,6 @@ void svc_send(struct svc_rqst *rqstp)
 	status = xprt->xpt_ops->xpo_sendto(rqstp);
 
 	trace_svc_send(rqstp, status);
-	svc_xprt_release(rqstp);
 }
 
 /*
@@ -964,7 +922,7 @@ void svc_send(struct svc_rqst *rqstp)
  */
 static void svc_age_temp_xprts(struct timer_list *t)
 {
-	struct svc_serv *serv = from_timer(serv, t, sv_temptimer);
+	struct svc_serv *serv = timer_container_of(serv, t, sv_temptimer);
 	struct svc_xprt *xprt;
 	struct list_head *le, *next;
 
@@ -1056,6 +1014,19 @@ static void svc_delete_xprt(struct svc_xprt *xprt)
 	struct svc_serv	*serv = xprt->xpt_server;
 	struct svc_deferred_req *dr;
 
+	/* unregister with rpcbind for when transport type is TCP or UDP.
+	 */
+	if (test_bit(XPT_RPCB_UNREG, &xprt->xpt_flags)) {
+		struct svc_sock *svsk = container_of(xprt, struct svc_sock,
+						     sk_xprt);
+		struct socket *sock = svsk->sk_sock;
+
+		if (svc_register(serv, xprt->xpt_net, sock->sk->sk_family,
+				 sock->sk->sk_protocol, 0) < 0)
+			pr_warn("failed to unregister %s with rpcbind\n",
+				xprt->xpt_class->xcl_name);
+	}
+
 	if (test_and_set_bit(XPT_DEAD, &xprt->xpt_flags))
 		return;
 
@@ -1066,8 +1037,8 @@ static void svc_delete_xprt(struct svc_xprt *xprt)
 
 	spin_lock_bh(&serv->sv_lock);
 	list_del_init(&xprt->xpt_list);
-	WARN_ON_ONCE(!list_empty(&xprt->xpt_ready));
-	if (test_bit(XPT_TEMP, &xprt->xpt_flags))
+	if (test_bit(XPT_TEMP, &xprt->xpt_flags) &&
+	    !test_bit(XPT_PEER_VALID, &xprt->xpt_flags))
 		serv->sv_tmpcnt--;
 	spin_unlock_bh(&serv->sv_lock);
 
@@ -1117,36 +1088,26 @@ static int svc_close_list(struct svc_serv *serv, struct list_head *xprt_list, st
 	return ret;
 }
 
-static struct svc_xprt *svc_dequeue_net(struct svc_serv *serv, struct net *net)
+static void svc_clean_up_xprts(struct svc_serv *serv, struct net *net)
 {
-	struct svc_pool *pool;
 	struct svc_xprt *xprt;
-	struct svc_xprt *tmp;
 	int i;
 
 	for (i = 0; i < serv->sv_nrpools; i++) {
-		pool = &serv->sv_pools[i];
-
-		spin_lock_bh(&pool->sp_lock);
-		list_for_each_entry_safe(xprt, tmp, &pool->sp_sockets, xpt_ready) {
-			if (xprt->xpt_net != net)
-				continue;
-			list_del_init(&xprt->xpt_ready);
-			spin_unlock_bh(&pool->sp_lock);
-			return xprt;
+		struct svc_pool *pool = &serv->sv_pools[i];
+		struct llist_node *q, **t1, *t2;
+
+		q = lwq_dequeue_all(&pool->sp_xprts);
+		lwq_for_each_safe(xprt, t1, t2, &q, xpt_ready) {
+			if (xprt->xpt_net == net) {
+				set_bit(XPT_CLOSE, &xprt->xpt_flags);
+				svc_delete_xprt(xprt);
+				xprt = NULL;
+			}
 		}
-		spin_unlock_bh(&pool->sp_lock);
-	}
-	return NULL;
-}
 
-static void svc_clean_up_xprts(struct svc_serv *serv, struct net *net)
-{
-	struct svc_xprt *xprt;
-
-	while ((xprt = svc_dequeue_net(serv, net))) {
-		set_bit(XPT_CLOSE, &xprt->xpt_flags);
-		svc_delete_xprt(xprt);
+		if (q)
+			lwq_enqueue_batch(q, &pool->sp_xprts);
 	}
 }
 
@@ -1154,6 +1115,7 @@ static void svc_clean_up_xprts(struct svc_serv *serv, struct net *net)
  * svc_xprt_destroy_all - Destroy transports associated with @serv
  * @serv: RPC service to be shut down
  * @net: target network namespace
+ * @unregister: true if it is OK to unregister the destroyed xprts
  *
  * Server threads may still be running (especially in the case where the
  * service is still running in other network namespaces).
@@ -1166,7 +1128,8 @@ static void svc_clean_up_xprts(struct svc_serv *serv, struct net *net)
  * threads, we may need to wait a little while and then check again to
  * see if they're done.
  */
-void svc_xprt_destroy_all(struct svc_serv *serv, struct net *net)
+void svc_xprt_destroy_all(struct svc_serv *serv, struct net *net,
+			  bool unregister)
 {
 	int delay = 0;
 
@@ -1176,6 +1139,9 @@ void svc_xprt_destroy_all(struct svc_serv *serv, struct net *net)
 		svc_clean_up_xprts(serv, net);
 		msleep(delay++);
 	}
+
+	if (unregister)
+		svc_rpcb_cleanup(serv, net);
 }
 EXPORT_SYMBOL_GPL(svc_xprt_destroy_all);
 
@@ -1306,6 +1272,40 @@ static struct svc_deferred_req *svc_deferred_dequeue(struct svc_xprt *xprt)
 }
 
 /**
+ * svc_find_listener - find an RPC transport instance
+ * @serv: pointer to svc_serv to search
+ * @xcl_name: C string containing transport's class name
+ * @net: owner net pointer
+ * @sa: sockaddr containing address
+ *
+ * Return the transport instance pointer for the endpoint accepting
+ * connections/peer traffic from the specified transport class,
+ * and matching sockaddr.
+ */
+struct svc_xprt *svc_find_listener(struct svc_serv *serv, const char *xcl_name,
+				   struct net *net, const struct sockaddr *sa)
+{
+	struct svc_xprt *xprt;
+	struct svc_xprt *found = NULL;
+
+	spin_lock_bh(&serv->sv_lock);
+	list_for_each_entry(xprt, &serv->sv_permsocks, xpt_list) {
+		if (xprt->xpt_net != net)
+			continue;
+		if (strcmp(xprt->xpt_class->xcl_name, xcl_name))
+			continue;
+		if (!rpc_cmp_addr_port(sa, (struct sockaddr *)&xprt->xpt_local))
+			continue;
+		found = xprt;
+		svc_xprt_get(xprt);
+		break;
+	}
+	spin_unlock_bh(&serv->sv_lock);
+	return found;
+}
+EXPORT_SYMBOL_GPL(svc_find_listener);
+
+/**
  * svc_find_xprt - find an RPC transport instance
  * @serv: pointer to svc_serv to search
  * @xcl_name: C string containing transport's class name
@@ -1408,29 +1408,36 @@ int svc_xprt_names(struct svc_serv *serv, char *buf, const int buflen)
 }
 EXPORT_SYMBOL_GPL(svc_xprt_names);
 
-
 /*----------------------------------------------------------------------------*/
 
 static void *svc_pool_stats_start(struct seq_file *m, loff_t *pos)
 {
 	unsigned int pidx = (unsigned int)*pos;
-	struct svc_serv *serv = m->private;
+	struct svc_info *si = m->private;
 
 	dprintk("svc_pool_stats_start, *pidx=%u\n", pidx);
 
+	mutex_lock(si->mutex);
+
 	if (!pidx)
 		return SEQ_START_TOKEN;
-	return (pidx > serv->sv_nrpools ? NULL : &serv->sv_pools[pidx-1]);
+	if (!si->serv)
+		return NULL;
+	return pidx > si->serv->sv_nrpools ? NULL
+		: &si->serv->sv_pools[pidx - 1];
 }
 
 static void *svc_pool_stats_next(struct seq_file *m, void *p, loff_t *pos)
 {
 	struct svc_pool *pool = p;
-	struct svc_serv *serv = m->private;
+	struct svc_info *si = m->private;
+	struct svc_serv *serv = si->serv;
 
 	dprintk("svc_pool_stats_next, *pos=%llu\n", *pos);
 
-	if (p == SEQ_START_TOKEN) {
+	if (!serv) {
+		pool = NULL;
+	} else if (p == SEQ_START_TOKEN) {
 		pool = &serv->sv_pools[0];
 	} else {
 		unsigned int pidx = (pool - &serv->sv_pools[0]);
@@ -1445,6 +1452,9 @@ static void *svc_pool_stats_next(struct seq_file *m, void *p, loff_t *pos)
 
 static void svc_pool_stats_stop(struct seq_file *m, void *p)
 {
+	struct svc_info *si = m->private;
+
+	mutex_unlock(si->mutex);
 }
 
 static int svc_pool_stats_show(struct seq_file *m, void *p)
@@ -1456,12 +1466,11 @@ static int svc_pool_stats_show(struct seq_file *m, void *p)
 		return 0;
 	}
 
-	seq_printf(m, "%u %llu %llu %llu %llu\n",
-		pool->sp_id,
-		percpu_counter_sum_positive(&pool->sp_sockets_queued),
-		percpu_counter_sum_positive(&pool->sp_sockets_queued),
-		percpu_counter_sum_positive(&pool->sp_threads_woken),
-		percpu_counter_sum_positive(&pool->sp_threads_timedout));
+	seq_printf(m, "%u %llu %llu %llu 0\n",
+		   pool->sp_id,
+		   percpu_counter_sum_positive(&pool->sp_messages_arrived),
+		   percpu_counter_sum_positive(&pool->sp_sockets_queued),
+		   percpu_counter_sum_positive(&pool->sp_threads_woken));
 
 	return 0;
 }
@@ -1473,14 +1482,18 @@ static const struct seq_operations svc_pool_stats_seq_ops = {
 	.show	= svc_pool_stats_show,
 };
 
-int svc_pool_stats_open(struct svc_serv *serv, struct file *file)
+int svc_pool_stats_open(struct svc_info *info, struct file *file)
 {
+	struct seq_file *seq;
 	int err;
 
 	err = seq_open(file, &svc_pool_stats_seq_ops);
-	if (!err)
-		((struct seq_file *) file->private_data)->private = serv;
-	return err;
+	if (err)
+		return err;
+	seq = file->private_data;
+	seq->private = info;
+
+	return 0;
 }
 EXPORT_SYMBOL(svc_pool_stats_open);